The purpose of this study is to illustrate how the combined use of qualitative and quantitative methods were necessary in obtaining within this society a clearer understanding of incest. The paper opens with a report of studies carried out on natural father and stepfather incestuous families, and this opens up the issue of the appropriateness of both types of research methodologies. Differences found in the types of incest, and responses of families to treatment, illustrate findings that would not have been uncovered had either methodology been used to the exclusion of the other. The argument is made that the dichotomization of quantitative and qualitative techniques is both misleading and unnecessary. The methodological issues are rather ones of judgment about what will yield needed information in a given investigation. The paper also gives some attention to the related issue of which methodological approaches are appropriate when a fresh line of inquiry is beginning in a field; and mention is made of an obvious issue that arises in dealing with incest--the handling of "sensitive" research problems. (Author/JAZ)